Such a gas bag module comprises a housing for an inflator and a retaining ring for a gas bag, which are both formed of a plastic material, and further a cover for the gas bag.
Such a gas bag module, which is known from U.S. Pat. No. 5,839,751, is meanwhile a usual vehicular component, this being the reason why its functioning is not detailed in the following. One emphasis on which further development of known gas bag modules concentrates is to simplify or facilitate their production without affecting the properties of the gas bag module.
Following activation of the inflator which translates the gas bag from its compact folded condition into its deployed condition, a high pressure occurs in the interior of the housing; apart from this the housing is exposed to a hot gas jet. It is for these reasons that it has until recently been assumed that only housings of metal are able to withstand the stresses occurring during activation. This applies also to the retaining ring with which the gas bag is secured to the housing. It has been assumed until recently that only a retaining ring of metal offers the required strength so that the gas bag is secured to the housing during deployment with the necessary reliability. The above mentioned document provides a gas bag module wherein the housing and the retaining ring are made of a plastic material, this being based on the discovery that plastic materials alone are already able to satisfy the requirements demanded of the housing and the retaining ring of a gas bag module. In addition to this, a housing of plastic material can be fabricated much more cost effectively than a housing of metal, thus cost benefits materialize during production. Furthermore, a housing of plastic material, which can be injection molded, for instance, can be fabricated in very much more complex designs than a conventional housing of metal so that a housing in accordance with the invention can be adapted very simply to the specific conditions of application. However, fabricating and mounting the gas bag cover at the housing still poses a problem since these usually involve complicated manufacturing and mounting steps.